So I just moved 120,000 MR points into SPG (60,000 with the bonus) to US where it will become 75,000+37,500=112,500.

While I "lose" 7,500 points in the transfer, I avoided the $99 ff excise tax AMEX would charge on a direct transfer to an airline program. At 2% those 7,500 miles are worth $150, so with saving the $99 this is pretty close to a wash on a 1:1 ratio.

At .0006 per mile fee on MR airline transfers, would that not be $72 and not $99? Just a data point...